The present invention relates to a noise prevention apparatus for a cable winch elevator, and more particularly, to a noise prevention apparatus for an elevator in which the noise that leaks to the outside of the machine room on the top floor to which a cable winch elevator is provided, and which is caused by vibration accompanying the rotational drive of the cable winch and the like, is reduced.
In general, elevators or lifts are defined as apparatus that use electrical or other drive means to convey persons and freight up and down. These elevators, comprise a cable winch usually provided in a machine room on the top floor of the building; a main sheave; a governor and controller apparatus; a cage that runs up and down and which is positioned in a hoistway that is provided vertically so as to pass through each floor of the building; a counterweight; guide rails for both the cage and the counterweight; and shock absorbers for both the cage and the counterweight. The ends of the cable that is wound around the main sheave are fixed to the cage and the counterweight respectively, and this cable moves in both the up and down directions accompanying slight movement through the cable holes located in at least two places in the floor of the machine room.
Accordingly, when the elevator is driven on the basis of commands from operation panels provided at the elevator doors on each floor, the motor of the cable winch generates vibration noise inside the machine room with the rotation of the main sheave, and this vibration noise is transmitted downwards via the cable holes and is transmitted as noise inside the hoistway for the elevator and to the inside of the cage.
Because of this, the "Elevator Noise Prevention Apparatus" disclosed in Japanese Utility Model Application Laid-Open Publication No. 57-106670 (1983) and shown in FIG. 1, has been proposed in order to prevent the transmission of vibration noise to the inside of the elevator cage. In FIG. 1, an elevator 10 comprises a winch 11, a main sheave 12 that is mounted on the motor (not indicated in the figure) of the winch 11, a cable 13 that is wound around the main sheave 12, and an elevator cage 14 and a counterweight 15 which are fixed to respective ends of the cable 13. A control apparatus 16 that controls the drive of the motor (not indicated in the figure) is built into the winch 11 and the floor 17 of a machine room in which the winch 11 and the main sheave 12 are located is pierced by two cable holes 18 through which the cable 13 moves up and down.
The lower side of the machine room in which the winch 11 and the like are located is a hoistway 19 for the elevator on the other side of the floor 17 and the opening portions on each floor linked by the hoistway 19 are provided with doors 20 so that when these doors are opened, the elevator cage 14 is linked with the elevator hall 21 via the opening portions.
In addition, the configuration is such that the vibration noise of an elevator such as this does not leak in the direction of the elevator hall 21, the elevator cage 14, and the elevator hoistway 19 because of a conventional vibration noise prevention apparatus 25. This vibration noise prevention apparatus 25 comprises a cylindrical noise prevention duct 26 located at the floor 17 so as to allow a slight amount of sway accompanying the up and down motion of the cable 13 on the upper side of the openings of the cable holes 18, and a noise absorption material 27 that is provided so as to surround the cable on the surface of the inner circumference of the cylindrical noise prevention duct 26. Also, the entire winch 11 is not directly mounted on the floor 17 but is mounted on a damper member 28 so as to prevent the transmission of vibration noise to the lower side of the machine room. This damper member 28 also comprises the cylindrical noise prevention duct 26, the noise absorption material 27 and the vibration noise prevention apparatus 25.
However, even if the conventional vibration noise prevention apparatus 25 having the configuration described above is provided, there must be the necessary minimum gap between the cable 13 and the noise absorption material 27 so as to permit a slight amount of sway of the cable 13 when it moves up and down and there is the problem that the vibration noise that is caused by driving the winch 11 is transmitted from this gap to the elevator cage 14 and the elevator hall 21.
In this manner, there have been proposed various countermeasures for the suppression of vibration of the winch 11 itself and for the provision of vibration noise prevention apparatus 25 having the conventional configuration described above. For example, when a motor (not indicated in the figure) is provided inside the winch 11, it is fixed by bolts with rubber or some other noise absorbing material there between, and other noise absorbing material is wrapped around the outside of the motor itself, while squeaking and other noises occurring between the main sheave 12 and the output shaft of the motor are prevented by a high-precision gear mechanism and the like. The external transmission of vibration can be prevented in such a manner but when these noise prevention means are implemented for apparatus such as the winch 11 in the machine room, the apparatus itself increases in size and the effective space inside the machine room is reduced and there is the new problem of an increase in the elevator manufacturing cost.